Electron-discharge device



' Patente d 29, 1925.

UNITED ,STATS PATENT OFFICE.

JOSEPH B. ZE1KA, OF NUTLEY, JERSEY, ASSIGNOR T BRIGHISON LABORA-- TOBIES, INC., OF NEW YORK,"N. Y., A CORPORATION OF NEW YOBK.

' ELECTRON-DISCERGE DEVIOE.

Application flled June 24, 1924. Serial No. 722,076.

To all whom zt may concem:

Be it' known, that I, JOSEPH B. ZEIKA, -a citizen of the United States, and a resident of Nutley, county of Essex, and State of New Jersey, have invented certain new and useful Improvements in Electron-Discharge Devices, of which the following is a full, clear, concise, and exact description.

While m invention is capable of a broad field of ut1lity, I will, for the purpose of convenience, describe and illustrate in connection with an evacated vessel or tube which is intended to be employed for the purpose generally of rectifying currcnts and more particularly for rectifying, detecting, oscillating and amplifying currents bothmf the audio and of radio. frequency in the reoeption and transmission of waves et radio fr uericies; and while for purposcs of convemence, I will hereinafter refer to m invention as employed to such end, it will be .understood that this ,is doge for convenien only, and that as far as the claims permit, the invention is capable of a broader field of utility.

In the multi-element vacuum tube as for instance, the 3-element tube illustrated in the drawings, the operation of the tube for the purpose intended is tied u more or less with the manner in which t e filament is supported, since I have discovered that the m1crophonic noises frequently, if not general ly, present when such tubes are used,

is due in part if not wholly to the manner in which the filament issupported, with the expansion andcontraction of the filament incident to its hcating as a current is passed' therethrough, not only .does thefilament tend to maintain its predetermined parallel assoiation with the rest of the elements of the tube, but in addition the tension under which the filament is maintained, will vary from time to time.

One ofthe important objects of my invention, therefore, is an arrangement for 80 supporting the filament as to maintain such filament at all'times, not only in its redetermined position but also in the desired predetermined tension to cause the tube to operate at all times at a uniform and maxi- -mum efliciency. 4

For the purpose of attaining these objects and such other objects as may herc- 1nafter a pear or be pointed out, I have illustrat one embodiment of my invention in connection with the process employed by me in the drawings, wherein Fig. 1 shows the stem of the tube with the various elements assembled thereon and the leads thereto;

Fig. 2 .is the top plan view of this assembly;

Fig.3 shows the first step in the association of the filament inthe assembly;

Fig. 4 a second step in such association;

Fig. 5, the filament in its final assembled form on the stem.

Before describing my invention, I will premisc that the embodimcnt in connection With which my invention has been illustrated, is a conventional type of radio tube in which there is fixed a glass stem 10 having mbedded therein and passing therethrough the four leads, two of which are filament leads 11 and 12, one of which is the plate lead 13 .and the fourth of which is a grid lead 14. There are also embcdded in the stem 10 the three supports 15, 16 and 17, one for each of the three elements of the tube. In Fig. 1 of the drawing, I have illustrated a stem of this Character with the leads and anchor enibedded therein.

The filament support 16 in Fig. 3, it will be observed, is embedded in the stem 10 at 21, is bent at 22, to offset the upper part thereof to the side of the plate 23 so as to provide room for the plate, and it will therefore be understood that the filament stem while positioned along the line of the short central axis of the stem, is displaced to the side of the central longitudinal axis thereof. I attach in any preferrcd or desired manner to the upper part of the filament support 16 the filament anchoring element 24, preferably, although not nccessarly, made of molybdenum which 'S purposely given the shapc and character shown 111 Fig.!) 01' the drawing in the manner and for the purpose which I will now more fully set forth.

The anchor piece 24 'is first bent at its outer free end to form the upwardly opening hook 25, in which is received the fila- 'ment 26 and is then held substantially in the position shown in Fig. 3"with the anchor 105 piece against the s'upfport 16 and at an angle thereto, the hook 25 rst having been passed under the filament so as to catch therebeneath, and the position of the anchor piece with reference to the lengthbf the filament 110 26 being such that the filament is held extended for its normal length. And the anchor member 24 is then fixed in 1ts position by being secured to the support 16 as by spot Weldmg.

It will, of course, be understood upon observing Fig. 3 that this anchor piece 24 1s angularly positioned with reference to the support 16 and is so positioned that the filament 26 is fully extended. I now snn ultaneously form the downwardly opemn bend 28 (sec Fig. 4) in this anchor piece an at the same time move the anchor piece 24 as a whole so as to cause it to assume the horizontal position, the bend 28 being of such a character and such a size as to cause the hook portion 25 to be moved above the position upon which it preliminarily occupied, as in Fig. 3 of the drawing. In other words, as a result of this operation upon the anchor piece 24, the anchor piece as a whole has moved downward to its horizontal position, but the hook 25 has been caused to move reversely, that is upwardly, and due to the formation of the bend 28, will occupy e. position somewhat nearer the support 16 than it did originally. This raising of the hook 25 will produce an upward pull on the filament, and due to the relative inextensibility of the filament, will be sprun slightly downwardly. In other words, in t is manner I not only support the filament fully extended, but the filament when so supported tends to move the anchor piece 24 downwardly from its normal. As a result of this, any expansion of the filament resulting from. its being heated will be taken up by the movement of the anchor piece 24 towards its normal horizontal position.

In this manner, I have obtained a Support for the filament which is inexpensive to make and easy to position, but which in its normal operation unctions to maintain the filament at all times properl positioned and fully extended, and that t i's functioning of the filament sup ort is obtained without the employment o any extraneous features and merely by givin to the member 28 the reverse bends and the angular movement as set forth.

to secure by Letters Patent is:

- permanent ben sion.

' 2. In a device of the character described, in combination, a support, a filament carrying member secured thereto and extendingangularly therefrom, said member having its free end curved into an ogee with the upwardly opening part of the ogee positioned at the extreme end wnereby afilament carried from such free end may be maintained under the desired spring tenmon 3. The pr0cess of*supporting a filament under spring tension WhlCh comprises first supporting a filament from a resilicnt member and then placing the member under elastic stress by putting a permanent bend therein whereby the filament will be supported under such stress and the member will accommodate itself to the contraction and expansion of the filament to always maintain said filament in fully extended condition.

4. The process of supporting a filament under sprmg tension Wh1ch comprises first supporting a filament from a resilient member and then placing the member under elastic stress by bending it into an ogee whereby the filament will be supported under such stress and the member Will accommodate itself to the contraction and expansion of the filament to always maintain said filament in full extended condition.

5. The process o tensionin a filament supported from the hook o? a resilient member which grocess consists in placing a in said member so as to place it under elastic stress, whereby the filament will be supported under such stress and the member v vill accommodate itself to the contraction and expansion of the filament to always maintain said filament in filly extended, condition.

In testimony whereof, I have signed this specification,.this 2lst day of J une, 1924.

J OS. B. ZETKA. 

